support letsencrypt (#56)

* Add more serialization formats to JWS * Add ES384 keys * Allow creating JWK from x509 keys directly * Allow adding extra headers * Cleanup and add tests * Add changes to CHANGES.md
ulrikstrid · Feb 16, 2023 · 8959edd · 8959edd
1 parent ad829c5
commit 8959edd
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diff --git a/CHANGES.md b/CHANGES.md
@@ -1,3 +1,10 @@
+next
+--------------
+- Support all serialization formats, previously only the compact serialization was supported, now we support both general and flattened JSON format (by @ulrikstrid) 
+- Add support for ES384 (P-384 with SHA384) (by @ulrikstrid) 
+- Allow creating a JWK from X509 keys directly (by @ulrikstrid) 
+- Support extra headers (by @ulrikstrid) 
+
 0.8.2
 --------------
 - JWS now properly checks the signature. Reported by @nankeen and fixed by @ulrikstrid. CVE-2023-23928

diff --git a/jose/Header.ml b/jose/Header.ml
@@ -2,17 +2,26 @@ open Utils
 
 type t = {
   alg : Jwa.alg;
-  jku : string option;
   jwk : Jwk.public Jwk.t option;
   kid : string option;
   x5t : string option;
   x5t256 : string option;
   typ : string option;
   cty : string option;
   enc : Jwa.enc option;
+  extra : (string * Yojson.Safe.t) list option;
 }
 
-let make_header ?typ ?alg ?enc (jwk : Jwk.priv Jwk.t) =
+(* TODO: This is probably very slow *)
+let remove_supported (l : (string * Yojson.Safe.t) list) =
+  l |> List.remove_assoc "alg" |> List.remove_assoc "jwk"
+  |> List.remove_assoc "kid" |> List.remove_assoc "x5t"
+  |> List.remove_assoc "x5t#256"
+  |> List.remove_assoc "typ" |> List.remove_assoc "cty"
+  |> List.remove_assoc "enc"
+
+let make_header ?typ ?alg ?enc ?(extra = []) ?(jwk_header = false)
+    (jwk : Jwk.priv Jwk.t) =
   let alg =
     match alg with
     | Some alg -> alg
@@ -21,28 +30,41 @@ let make_header ?typ ?alg ?enc (jwk : Jwk.priv Jwk.t) =
         | Jwk.Rsa_priv _ -> `RS256
         | Jwk.Oct _ -> `HS256
         | Jwk.Es256_priv _ -> `ES256
+        | Jwk.Es384_priv _ -> `ES384
         | Jwk.Es512_priv _ -> `ES512)
   in
+  let kid =
+    match List.assoc_opt "kid" extra with
+    | Some kid -> Some (Yojson.Safe.Util.to_string kid)
+    | None -> Jwk.get_kid jwk
+  in
+  let extra = remove_supported extra in
   {
     alg;
-    jku = None;
-    jwk = None;
-    kid = Jwk.get_kid jwk;
+    jwk = (if jwk_header then Some (Jwk.pub_of_priv jwk) else None);
+    kid;
     x5t = None;
     x5t256 = None;
     typ;
     cty = None;
     enc;
+    extra = (match extra with [] -> None | extra -> Some extra);
   }
 
 module Json = Yojson.Safe.Util
 
+let get_extra_headers (json : Yojson.Safe.t) =
+  match json with
+  | `Assoc vals -> (
+      let extra = remove_supported vals in
+      match extra with [] -> None | extra -> Some extra)
+  | _ -> None (* TODO: raise here? *)
+
 let of_json json =
   try
     Ok
       {
         alg = json |> Json.member "alg" |> Jwa.alg_of_json;
-        jku = json |> Json.member "jku" |> Json.to_string_option;
         jwk =
           json |> Json.member "jwk"
           |> Json.to_option (fun jwk_json ->
@@ -56,6 +78,7 @@ let of_json json =
         enc =
           json |> Json.member "enc" |> Json.to_string_option
           |> U_Opt.map Jwa.enc_of_string;
+        extra = get_extra_headers json;
       }
   with Json.Type_error (s, _) -> Error (`Msg s)
 
@@ -64,17 +87,18 @@ let to_json t =
     [
       RJson.to_json_string_opt "typ" t.typ;
       Some ("alg", Jwa.alg_to_json t.alg);
-      RJson.to_json_string_opt "jku" t.jku;
-      U_Opt.map Jwk.to_pub_json t.jwk |> U_Opt.map (fun jwk -> ("jwk", jwk));
       RJson.to_json_string_opt "kid" t.kid;
+      U_Opt.map Jwk.to_pub_json t.jwk |> U_Opt.map (fun jwk -> ("jwk", jwk));
       RJson.to_json_string_opt "x5t" t.x5t;
       RJson.to_json_string_opt "x5t#256" t.x5t256;
       RJson.to_json_string_opt "cty" t.cty;
-      t.enc |> U_Opt.map Jwa.enc_to_string
+      t.enc
+      |> U_Opt.map Jwa.enc_to_string
       |> U_Opt.map (fun enc -> ("enc", `String enc));
     ]
   in
-  `Assoc (U_List.filter_map (fun x -> x) values)
+  let extra = Option.value ~default:[] t.extra in
+  `Assoc (U_List.filter_map (fun x -> x) values @ extra)
 
 let of_string header_str =
   U_Base64.url_decode header_str

diff --git a/jose/Jose.mli b/jose/Jose.mli
@@ -6,6 +6,7 @@ module Jwa : sig
     [ `RS256  (** HMAC using SHA-256 *)
     | `HS256  (** RSASSA-PKCS1-v1_5 using SHA-256 *)
     | `ES256  (** ECDSA using P-256 and SHA-256 *)
+    | `ES384  (** ECDSA using P-384 and SHA-384 *)
     | `ES512  (** ECDSA using P-521 and SHA-512 *)
     | `RSA_OAEP  (** RSAES OAEP using default parameters *)
     | `RSA1_5  (** RSA PKCS 1 *)
@@ -79,6 +80,12 @@ module Jwk : sig
   type pub_es256 = Mirage_crypto_ec.P256.Dsa.pub jwk
   (** [es256] represents a private JWK with [kty] [`EC] and a [P256.priv] key *)
 
+  type priv_es384 = Mirage_crypto_ec.P384.Dsa.priv jwk
+  (** [es384] represents a public JWK with [kty] [`EC] and a [P384.pub] key *)
+
+  type pub_es384 = Mirage_crypto_ec.P384.Dsa.pub jwk
+  (** [es384] represents a private JWK with [kty] [`EC] and a [P384.priv] key *)
+
   type priv_es512 = Mirage_crypto_ec.P521.Dsa.priv jwk
   (** [es512] represents a public JWK with [kty] [`EC] and a [P512.pub] key *)
 
@@ -92,6 +99,8 @@ module Jwk : sig
     | Rsa_pub : pub_rsa -> public t
     | Es256_priv : priv_es256 -> priv t
     | Es256_pub : pub_es256 -> public t
+    | Es384_priv : priv_es384 -> priv t
+    | Es384_pub : pub_es384 -> public t
     | Es512_priv : priv_es512 -> priv t
     | Es512_pub : pub_es512 -> public t
 
@@ -154,6 +163,16 @@ module Jwk : sig
   (** [to_priv_pem t] takes a JWK and returns a result PEM string or a message
       of what went wrong. *)
 
+  val of_priv_x509 :
+    ?use:use ->
+    X509.Private_key.t ->
+    (priv t, [> `Msg of string | `Not_rsa ]) result
+
+  val of_pub_x509 :
+    ?use:use ->
+    X509.Public_key.t ->
+    (public t, [> `Msg of string | `Not_rsa ]) result
+
   val of_priv_json :
     Yojson.Safe.t ->
     ( priv t,
@@ -234,29 +253,39 @@ end
 module Header : sig
   type t = {
     alg : Jwa.alg;
-    jku : string option;
     jwk : Jwk.public Jwk.t option;
     kid : string option;
     x5t : string option;
     x5t256 : string option;
     typ : string option;
     cty : string option;
     enc : Jwa.enc option;
+    extra : (string * Yojson.Safe.t) list option;
   }
-  (** The [header] has the following properties: - [alg] Jwa - RS256 and none is
-      currently the only supported algs - [jku] JWK Set URL - [jwk] JSON Web Key
-      - [kid] Key ID - We currently always expect this to be there, this can
-      change in the future - [x5t] X.509 Certificate SHA-1 Thumbprint -
-      [x5t#S256] X.509 Certificate SHA-256 Thumbprint - [typ] Type - [cty]
-      Content Type Not implemented: - [x5u] X.509 URL - [x5c] X.509 Certficate
-      Chain - [crit] Critical
+  (** The [header] has the following properties:
+  
+  - [alg] {! Jwa.alg }
+  - [jwk] JSON Web Key
+  - [kid] Key ID - We currently always expect this to be there, this can change in the future
+  - [x5t] X.509 Certificate SHA-1 Thumbprint -
+  - [x5t#S256] X.509 Certificate SHA-256 Thumbprint
+  - [typ] Type
+  - [cty] Content Type Not implemented
+  
+      {{: https://tools.ietf.org/html/rfc7515#section-4.1 } Link to RFC }
 
-      {{: https://tools.ietf.org/html/rfc7515#section-4.1 } Link to RFC } *)
+      {{: https://www.iana.org/assignments/jose/jose.xhtml#web-signature-encryption-header-parameters } Complete list of registered header parameters} *)
 
   val make_header :
-    ?typ:string -> ?alg:Jwa.alg -> ?enc:Jwa.enc -> Jwk.priv Jwk.t -> t
+    ?typ:string ->
+    ?alg:Jwa.alg ->
+    ?enc:Jwa.enc ->
+    ?extra:(string * Yojson.Safe.t) list ->
+    ?jwk_header:bool ->
+    Jwk.priv Jwk.t ->
+    t
   (** [make_header typ alg enc jwk] if [alg] is not provided it will be derived
-      from [jwk]. *)
+      from [jwk]. [jwk_header] decides if the jwk should be put in the header. *)
 
   val of_string : string -> (t, [> `Msg of string ]) result
   val to_string : t -> string
@@ -277,8 +306,12 @@ module Jws : sig
     signature : signature;
   }
 
-  val of_string : string -> (t, [> `Msg of string ]) result
-  val to_string : t -> string
+  type serialization = [ `Compact | `General | `Flattened ]
+
+  val of_string :
+    string -> (t, [> `Msg of string | `Not_json | `Not_supported ]) result
+
+  val to_string : ?serialization:serialization -> t -> string
 
   val validate :
     jwk:'a Jwk.t -> t -> (t, [> `Invalid_signature | `Msg of string ]) result
@@ -315,15 +348,23 @@ module Jwt : sig
   val get_yojson_claim : t -> string -> Yojson.Safe.t option
   val get_string_claim : t -> string -> string option
   val get_int_claim : t -> string -> int option
-  val to_string : t -> string
+  val to_string : ?serialization:Jws.serialization -> t -> string
 
   val of_string :
     jwk:'a Jwk.t ->
     string ->
-    (t, [> `Expired | `Invalid_signature | `Msg of string ]) result
+    ( t,
+      [> `Expired
+      | `Invalid_signature
+      | `Msg of string
+      | `Not_json
+      | `Not_supported ] )
+    result
   (** [of_string ~jwk jwt_string] parses and validates the encoded JWT string. *)
 
-  val unsafe_of_string : string -> (t, [> `Msg of string ]) result
+  val unsafe_of_string :
+    string -> (t, [> `Msg of string | `Not_json | `Not_supported ]) result
+
   val to_jws : t -> Jws.t
   val of_jws : Jws.t -> t
 

diff --git a/jose/Jwa.ml b/jose/Jwa.ml
@@ -20,6 +20,7 @@ type alg =
   [ `RS256  (** HMAC using SHA-256 *)
   | `HS256  (** RSASSA-PKCS1-v1_5 using SHA-256 *)
   | `ES256  (** ECDSA using P-256 and SHA-256 *)
+  | `ES384  (** ECDSA using P-384 and SHA-384 *)
   | `ES512  (** ECDSA using P-521 and SHA-512 *)
   | `RSA_OAEP  (** RSAES OAEP using default parameters *)
   | `RSA1_5  (** RSA PKCS 1 *)
@@ -30,6 +31,7 @@ let alg_to_string = function
   | `RS256 -> "RS256"
   | `HS256 -> "HS256"
   | `ES256 -> "ES256"
+  | `ES384 -> "ES384"
   | `ES512 -> "ES512"
   | `RSA_OAEP -> "RSA-OAEP"
   | `RSA1_5 -> "RSA1_5"
@@ -40,6 +42,7 @@ let alg_of_string = function
   | "RS256" -> `RS256
   | "HS256" -> `HS256
   | "ES256" -> `ES256
+  | "ES384" -> `ES384
   | "ES512" -> `ES512
   | "RSA-OAEP" -> `RSA_OAEP
   | "RSA1_5" -> `RSA1_5

diff --git a/jose/Jwe.ml b/jose/Jwe.ml
@@ -104,6 +104,8 @@ let encrypt_cek (type a) alg (cek : string) ~(jwk : a Jwk.t) =
   | Oct _ -> Error `Unsupported_kty
   | Es256_priv _ -> Error `Unsupported_kty
   | Es256_pub _ -> Error `Unsupported_kty
+  | Es384_priv _ -> Error `Unsupported_kty
+  | Es384_pub _ -> Error `Unsupported_kty
   | Es512_priv _ -> Error `Unsupported_kty
   | Es512_pub _ -> Error `Unsupported_kty)
   >>= fun key ->